为什么R不存在错误进入android？

Question

packages/apps/Myfolder/src/com/android/myfolder/MyFile.java:196: package R does not exist
                  addPreferencesFromResource(R.xml.myfile);
                                              ^
packages/apps/Myfolder/src/com/android/myfolder/MyFile.java:344: package R does not exist
        menu.add(0, MENU_SAVE, 0, R.string.menu_save)
                                   ^
packages/apps/Myfolder/src/com/android/myfolder/MyFile.java:346: package R does not exist
        menu.add(0, MENU_CANCEL, 0, R.string.menu_cancel)
                                     ^
packages/apps/Myfolder/src/com/android/myfolder/MyFile.java:454: package R does not exist
                     errorMsg = mRes.getString(R.string.error_empty);
                                                ^
packages/apps/Myfolder/src/com/android/myfolder/MyFile.java:458: package R does not exist
                     errorMsg = mRes.getString(R.string.error_empty);

Answer 1

在我的情况下,发生此错误是因为我更改了应用程序的程序包名称(当然,在发布到Google Play之前),但我忘了更新文件中元素的package属性.一旦属性与新包名一致,错误就消失了.manifestAndroidManifest.xmlpackage

Answer 2

确保你有:在调用R class的java文件中打包'YOUR PACKAGE NAME'

Answer 3

检查资源文件中是否存在任何错误或任何缺少的依赖项.这些中的任何一个都会导致R.java类不是代码生成的,因此会出现许多错误,例如您所显示的错误.